Concave.



P. W. LARsoN.

GONGAVE.

APPLICATION FILED APB. 8, 1911.

Patented Aug. 6, 1912. v

4[Il V Allll COLUMBIA PLANOGRAPM c0..wAsmNuToN. D. c.

:PAUL W. LARSON, OF SWEA CITY, IOWA.

CONCAVE.

Specification of Letters Patent.

Application filed April 8, 1911.

Patented Ang. 6, 1912. Serial No. 619,743.

To all whom 'it may concern:

Be it known that I, PAUL W. LARsoN, a citizen of the United States,residing at Swea City, in the county of Kossuth and State of Iowa, haveinvented new and useful Improvements in Conca-ves, of which thefollowing is a specication.

This invention relates to threshing machines and more particularly toconcaves therefor.

The object of the invention is to provide an auxiliary concave havingmovable teeth which may be thrown into or out of operative position withrelation to the cylinder teeth when desired.

rlhe invention embodies an auxiliary grate p having separate shaftsmounted therein with teeth thereon arranged in staggered relation, and aworm screw connected to each of the shafts through suitable levers forturning the shafts whereby the teethmay be carried into or out ofoperative position.

Further objects of the invention will appear as the following specificdescription is read in connection with the accompanying drawings, whichform a part of this application, and in which Figure 1 is a sectiontaken through a threshing machine showing the cylinder and concave inelevation therein. Fig. 2 is a section on the line 2 2 of Fig. 1. Fig. 3is an enlarged detail sectional view on the line 3-3 of Fig. 2.

Referring more particularly to the drawing, 1 represents the cylindersha-ft upon which the cylinder 2 is mounted. This cylinder is providedwith the usual cylinder teeth 3 which travel over the concave 4 and inbetween the teeth carried thereby.

Mounted in the hangers 5 secured to the frame of the machine, not shown,is a grate or auxiliary concave 6 which is provided with separate rowsof slots 7 the slots in one rowk alternating with those in the adjoiningrow. The under side of each grate has the webs 8 beneath the slotextended downwardly and provided with transverse openings in which arejournaled the shafts 9 and 10, both of which being provided withtransverse openings l1 to receive the auxiliary concaved teeth 12. Ateach end of these shafts there are secured suitable levers 13 and 14which have pivotally connected to their ends the internally threadednuts 15 engaged by the worm screws 16, whose operating shafts 17 extendto the outside of the machine and are provided with cranks 18 by whichthey may be rotated in either direction. Longitudinal webs 19 extendacross the grate sections 6 and form abutments for the teeth 12 when therear edge of the forward abutments are inclined, as shown at 20, vso asto provide a rest and limiting stop for the rear teeth 12. The concaveteeth and auxiliary concave may be mounted in the ordinary machine andeither one or the other of the shafts 9 and 10, or both of them, may beoperated so as to throw the teeth thereof out of operative positionwithout stopping the machine. lfilwo rows of auxiliary teeth are allthat are needed for different grains.

Having thus described the invention, what I claim as new is In aconcave, an auxiliary concave section having transverse bars withinclined faces, rods journaled immediataely below and in line with saidinclined faces, said rods carrying teeth, means for swinging said teethup into bearing Contact with the inclined faces, and for swinging saidteeth below said bars.

in testimony whereof l affix my signature in presence of two witnesses.

PAUL W. LARSON. Witnesses:

FRED Mmm, H. C. JOHNSON.

Copies of this patent may be obtained for i've cents each, by addressingthe Commissioner ci' Patents. Washington, D. C."

